While many people value self-confidence and self-belief very highly, it is actually a grave fault. Taken to its extreme, self-confidence can turn into madness. The question that is considered in this book is "what is a person is to believe in if he does not believe in himself?" In previous periods, this discussion could begin with the assumption that man is himself intrinsically sinful—that men, by nature, do evil things. However, in the modern period it has become fashionable to deny the existence of sin, so one might start, instead, with the belief that even if man cannot lose his soul through sin, he can at least lose his mind, and that this is a bad thing.

If everyone can agree that remaining sane is a good goal, then it would seem that imagination might be an intellectual pitfall. However, imagination is the friend of sanity, not its enemy; insane people generally are too given to reason. Many of them are incredibly logical and consistent, and their arguments are difficult to counter, even if they are plainly absurd. Many popular theories of the modern day have this same quality. Materialism—the theory that everything that exists is physical—has a certain consistency to it, but the picture it paints of the universe is too cramped and desolate. While the reasoning of these men could ultimately be shown to be faulty, the most effective route to changing their minds is along the lines of a personal and moral conversion to the idea that the universe is better and fuller than they believe it to be. It is necessary to show them that spiritual doctrines liberate the mind much more than their beliefs—whether it be the belief of a madman that everyone is out to destroy him or the belief of the materialist that men are mere beasts. By incorporating a certain amount of mystery, Christianity frees man from the necessity to reduce everything to the enslavement of pure logic.